Hydrolysis of aminonitriles



United States Patent 3,409,666 HYDROLYSIS OF AMINONITRILES Robert W. Foreman, Chagrin Falls, Ohio, assignor to The Standard Oil Company, Cleveland, Ohio, a corporation of Ohio No Drawing. Filed Jan. 24, 1966, Ser. No. 522,379 5 Claims. (Cl. 260-534) aminoacetic acids and salts thereof.

The aminoacetonitriles N CCH NCH CH N CH CN 2 and most preferred and then spray drying the mixture at a temperature of to produce an amino acid salt product of from 99.5 to 100% purity.

The stoichiometry for the preferred reaction is indicated by the following chemical equation:

The final colorless, solid strong acid, ion exchange, etc.

The instant process provides a rapid and substantially complete hydrolysis of nitrilotriacetonitrile to nitrilotri-' followed by the spray drying of the partially hydrolyzed mixture to produce the dry, substantially completely hydrolyzed product. In this process, essentially quantitative carbonate level of no more than 0.5%. The product assays at 99.5 to 100% trisodium salt monohydrate of nitrilotriacetic acid by cupric chloride titration. Preferably, process assays at 100% plus or minus 0.3%.

The time required for the entire instant process can be as short as about lO- mmutes from-the time the nitrilotr-i-- of aqueous sodium hydroxide.v This rapid maintained until the conversion level reaches about 70% the product produced by the instant aqueous solution, complete a matter of minutes. This result is indeed unobvious and unexpected.

acetonitrile preferably are tures in the range of 50 to 120 lower oxide in the form of the pre-hydrolyzed mixture before spray drying.

3,409,666 Patented Nov. 5, 1968 hydrolysis can be obtained in The initial hydrolysis step is carried out at tempera- C. Temperatures above C. can be maintained in a pressurized system. At temperatures, the hydrolysis reaction is too slow.

of liquid/hour may be used.

To insure that a pure white final product results, it is sometimes desirableto add a small amount, approximatebleaching agent such as hydrogen per- 30% aqueous hydrogen peroxide to The spray drying step in the process can be carried out feed and a method for separating the dry product from theexhaust gases. The equipment may be operated with countercurrent or concurrent gas-flow and may be heated 3,409,666 by oil, gas or coal-fired furnaces. The spray drying pref- EXAMPLE III erably done at a temperature from about 200 to 9000 In Table 111 the reaction mixture was composed of 3 The i gas temperaiures to the Spray dryer may vary moles of sodium hydroxide per mole of nitrilotriacetoniover a w de range but, in general, temperatures of from trile (NTN) and the mole ratio of water to NTN was about 300 to about 900 are Preferred The 46:1. All of the reactants were placed in the reactor at let t'mperature from the sprayodryer Preferably will once at about 150 mm. pressure. The spray drying rate wnhm'lfhe range of 200 to 350 may was 15 cc. per minute and a small amount of 30% aquep P by any one several convenuonal ous hydrogen peroxide was added before spray drying to 1 devices example hlfghlplzessure flmd decolorize the trisodium salt of nitrilotriacetic acid. nozzles and high speed mtatmg The Parade of This example, which is outside the scope of the present the final Product is not critical and it will depend upon invention, demonstrates that the initial hydrolysis temperature was too low and as a result, the final product the degree of atomization of the liquid slurry but this can was of too low purity to be of commercial value.

be varied over a wide range in accordance with techniques well knownin the art.

In general, the liquid solution or slurry of ingredients TABLE III is pumped into the atomizing device which in the case of H d l i ditions;

a countercurrent spray dryer is located near the top of Temperature C 40 the spray drying chamber. Hot gas is admitted at the bot- Ti ft r NTN ll added) days 2 tom of the chamber and flows upward countercun'ent to Weight 30% H O /wt. NTA 0.012

the descending globules of solid slurry to an exit at the Spray drying conditions:

top of the spray dryer. The product from the spray dryer Inlet air tem erature F 714 may be collected either continuously or intermittently as Outlet air temperature do 206 the size of the batch to be prepared and other considcra- Cyclone air temperature do 178 tions may dictate. Turbine air pressure p.s.i.g 30

Experiments illustrating the feasibility of the hydrolysis Analysis and results:

process described and claimed herein and the yields and Appearance White powder purities of the products that can be obtained are shown Percent NTA recovery 1 8 in the following examples. A specific process employed r y infrared analysis 8 N nitrilotriacetonitrile (NTN) as starting material and aque- EXAMPLE 1V ous sodium hydroxide as hydrolysis medium. Example I illustrates the process of the instant invention. Examples i lnoceidme of Example I g gif hs that ll-V illustrate processes which are outside the scope of t 6 5 was prqpared y mg 5 b aqueous sodium hydroxide to a mixture of NTN and ice in a Waring blender and the mixture was kept at ice bath ternperature. The slurry was composed of 3 moles of sodium the present invention.

EXAMPLE I hydroxide, one mole of NTN and 33.5 moles of water. The slurry was then spray-dried at a feed rate of 25 cc. Experiments A and B Shown 111 Table I each mp y per minute using an inlet temperature of 509 R, an outa reaction mixture of sodium hydroxide/NTN/water in let temperature of 250 F, d a cyclone i tgmpgrature the mole ratio of 3/1/26 9, respectively. Also in each of of 214 F. The product was yellow, smelled strongly of these experiments 0.026 gram per gram of NTN of 30% ammonia and assayed by CuCl assay only 10.3% triaqueous hydrogen peroxide was added to the mixture sodium salt of nitrilotriacetic acid. before spray drying, nitrogen stripping was employed during hydrolysis and p.s.i.:g. pressure was exerted on the EXAMPLE V spray dryer turbine. The NTN was twice recrystallized 45 A repeat of Example 11 where the reaction mixture B from water prior to use in these experiments. was given a further heat treatment at about 300 F. under TABLE I Mode of Temp. Time, Feed Inlet Air Outlet Air Cyclone Air Dried Percent NTA Recov- Percent NTA Ex. NTN addn. C.) Mm. Rate, Temp., F. Temp., 1?. Temp., F. Product ered Determined by by 011012 cc./mm. Color Weight Assay A--- 2/5 at 40 min -88 45 17 438 308 268 Pure white.. 100 bulk dens.=0.3l 99. as B".-. 2 5 at 40 min-. 80-88 34 17 43s 305 268 do 100.2 bulk dens=0.30 100 0 EXAMPLE II autogenous pressure for a fed minutes produced a dark colored product which assayed only 92% trisodium salt In Table II the mole ratio of sodium hydroxide to of nitrilotriacetic acid nitrilotriacetonitrile was 3:1 in experiments A and B. X This example is outside the scope of this invention and 60 E MPLE v1 illustrates that mere hydrolysis without the spray drying Results comparable to those in the preceding examples step is insuflicient to produce an acceptable product. were obtained when ethylene diamine tetra-acetonitrile TABLE II Hydrolysis Conditions Product Evaluation 0 Ex. Percent Conver- Mol Ratio Mode, Time Plus Tempera- Hydrolysis Hydrolysis Percent NHr Wt. 30% H202} Color sion to NTA H2OIN TN ture oi NTN Addition Temp, C. Time (Hours) Collected Wt. NTA (CuCl f T1tation ssay A 1 6. 1 Solid NTN gradually through 5. 7 84. 7 026 Very light 92. 3

out run, under vacuum. yellow solution.

5 35. 4 Plus H2O added during and after reaction. 13 22. 4 Add )6 portions of solid 86 3 81 013 Clear yellow 91. u

NTN every hour. solution.

1 Initial. Final.

5 was used as starting material in place of nitrilotriacetonitrile.

I claim: 1. The process for producing an aminoacid salt comprising partially hydrolyzing a mixture of water and substantially equivalent amounts of an aminonitrile selected perature of from about 50 to 120 C. and then spray drying the mixture at a temperature of from 200 to 900 F.

2. The process of claim 1 wherein the partial hydrolysis time is at least about one minute.

3. The process of claim 2 wherein the alkali metal hydroxide is sodium hydroxide.

4. The process of claim 3 wherein the aminonitrile is nitrilotriacetonitrile.

5. The process of claim 3 wherein the aminonitrile is ethylene diamine tetraacetonitrile.

References Cited UNITED STATES PATENTS 10/1958 Singer 260-534 5/1965 Singer et a1. 260534 LORRAINE A. WEINBERGER, Primary Examiner.

15 A. P. HALLUIN, Assistant Examiner. 

1. THE PROCESS FOR PRODUCING AN AMINOACID SALT COMPRISING PARTIALLY HYDROLYZING A MIXTURE OF WATER AND SUBSTANTIALLY EQUIVALENT AMOUNTS OF AN AMINONITRILE SELECTED FROM THE GROUP CONSISTING OF NITRILOTRIACETONITRILE, ETHYLENE DIAMINE TETRAACETONITRILE, DIETHYLENE TRIAMINE PENTAACETONITRILE, METHYLAMINE DIACETONITRILE, AND ETHYL AMINE DIACETONITRILE AND AN ALKALI METAL HYDROXIDE AT A TEMPERATURE OF FROM ABOUT 50 TO 120*C. AND THEN SPRAY DRYING THE MIXTURE AT A TEMPERATURE OF FROM 200 TO 900*F. 